Green beans are descendants of a common ancestor for all beans first cultivated in Peru. This ancestor, known as Phaseolus vulgaris, also produced kidney beans, black beans and navy beans.
Green beans are a long, bright green bean pod often containing three or more underdeveloped beans. The pod is crunchy when raw and softens with cooking. It is traditional to eat the entire pod with just the pointed ends and the string removed.
After cultivation, beans were grown widely throughout both Central America and the Southern tip of South America around the Andes. Green beans and other beans came to Europe during the 16th century, carried across the ocean by Spanish explorers. The food was further spread by Spanish and Portuguese traders, until it became a standard part of the diet in many cultures.
Today, green beans are grown all around the world, except on Antarctica. Multiple countries are large commercial producers of green beans, including China, Indonesia, Turkey and India. In 2010, China produced about 13 million tons of green beans. This is in comparison to the .88 million tons grown by the second-highest producer, Indonesia that same year. So, most green beans that people eat come from China.